1. Field of the Invention
The present invention relates to an integrated three phase separator having a vertical separation unit integrated with a horizontal separation unit.
2. Prior Art
Subterranean oil and gas which is produced from various types of production areas or stratas are intermixed resulting in an emulsion of hydrocarbon liquid such as oil, natural gas and water or brine. Various types of field processing separators have been used in the past to separate the mixture coming from a well head into its constituents of natural gas, hydrocarbon liquid such as oil, and water or brine.
Different types of separator vessels have been used in the past. Horizontal, cylindrical vessels typically have more gas capacity than vertical vessels of the same diameter. Vertical cylindrical vessels have also been used. In general, vertical vessels handle liquid slugs better than horizontal vessels.
In some cases, vessels in the prior art have attempted to utilize features of both horizontal and vertical vessels.
For example, Williams (U.S. Pat. No. 2,726,729) discloses a horizontal drum having vertical partitions within a three-phase horizontal separator with upright separator sections.
McCarter (U.S. Pat. No. 3,312,044) discloses a horizontal separator with an attached vertical section.
O'Neill et al. (U.S. Pat. No. 3,394,530) discloses a horizontal separator with a vertical section near one end of the horizontal section.
It is known that as a natural gas well ages, the gas pressure tends to be reduced. For example, wells that originally had bottom hole pressures of 1500 to 2500 psi might later have pressures of 200 psi. In some field operations, where the pressure has decreased over time, artificial lift devices and procedures are used to bring the natural gas and liquid hydrocarbons to the surface. This can result in periodic slugs of liquid entering the separator. Since the separator operates by gravity, periodic slugs or surges of liquid into the separator vessel are counterproductive to the separation process.
Accordingly, there is a need to provide a separator having both a horizontal cylindrical vessel and a vertical cylindrical vessel which are integrated into a single unit and which are easy to construct and manufacture.
There remains a need for an integrated horizontal and vertical separator which includes a mechanism to hold periodic surges of liquid in the vertical vessel and gently release them into the horizontal vessel.
There is additionally a need for an integrated horizontal and vertical separation unit which provides an equalizer/condenser mechanism between the gas areas of the vertical unit and the horizontal unit.